Obtenção de fibras de blendas de policaprolactona/poli (N-isopropilacrilamida) utilizando a técnica de eletrofiação

Abstract

From polymer blends it is possible to combine properties of polymers to obtain a new material. In this study, the polymers used in electrospinning were selected due to their distinct properties. Polycaprolactone (PCL) is a polymer that presents properties of toughness, ductility, hydrophobicity, low toxicity, ability to form blends with many polymers, in addition to being soluble in many organic solvents. Moreover, it is a biodegradable and biocompatible polymer. Poly (N-isopropylacrylamide) (PNIPAAm) is a biocompatible polymer which presents LCST phase diagram (Lower Critical Solution Temperature) in aqueous solution with transition temperature around 32 - 35°C, which makes it a thermorresponsive polymer, due to the hydrophilic- hydrophobic transition. However, the processing of this polymer can be produce brittle materials. Therefore it becomes very interesting to combine it with polymers having improved mechanical properties, such as PCL. Thus, the goal of this work was to carry out experiments in order to obtain PCL/PNIPAAm fiber blends from the solutions in different proportions, using the electrospinning technique. The electrospun fibers were characterized morphologically by optical microscopy (OM), scanning electron microscopy (SEM) techniques and by the wettability evaluation as a function of temperature, using static contact angle measurements. It was possible to get electrophilic fibers from solutions of PCL/PNIPAAm blends. The SEM and the contact angle (as function of the temperature) analysis of the electrospun fibers showed that the PNIPAAm amount had influenced on the morphological and on the wettability properties. Thus, these fibers present potential application in the field of tissue engineering or filtration membranes, among others.